docs: def parse_config(self):
          """Parse charm configuration and calculate values for config files."""
          config = config_get()
          mysql_config = {}
          if 'max-connections' in config:
              mysql_config['max_connections'] = config['max-connections']
  
          if 'wait-timeout' in config:
              mysql_config['wait_timeout'] = config['wait-timeout']
  
          if 'innodb-flush-log-at-trx-commit' in config:
              mysql_config['innodb_flush_log_at_trx_commit'] = \
                  config['innodb-flush-log-at-trx-commit']
          elif 'tuning-level' in config:
              mysql_config['innodb_flush_log_at_trx_commit'] = \
                  self.INNODB_FLUSH_CONFIG_VALUES.get(config['tuning-level'], 1)
  
          if ('innodb-change-buffering' in config and
                  config['innodb-change-buffering'] in self.INNODB_VALID_BUFFERING_VALUES):
              mysql_config['innodb_change_buffering'] = config['innodb-change-buffering']
  
          if 'innodb-io-capacity' in config:
              mysql_config['innodb_io_capacity'] = config['innodb-io-capacity']
  
          # Set a sane default key_buffer size
          mysql_config['key_buffer'] = self.human_to_bytes('32M')
          total_memory = self.human_to_bytes(self.get_mem_total())
  
          dataset_bytes = config.get('dataset-size', None)
          innodb_buffer_pool_size = config.get('innodb-buffer-pool-size', None)
  
          if innodb_buffer_pool_size:
              innodb_buffer_pool_size = self.human_to_bytes(
                  innodb_buffer_pool_size)
          elif dataset_bytes:
              log("Option 'dataset-size' has been deprecated, please use"
                  "innodb_buffer_pool_size option instead", level="WARN")
              innodb_buffer_pool_size = self.human_to_bytes(
                  dataset_bytes)
          else:
              # NOTE(jamespage): pick the smallest of 50% of RAM or 512MB
              #                  to ensure that deployments in containers
              #                  without constraints don't try to consume
              #                  silly amounts of memory.
              innodb_buffer_pool_size = min(
                  int(total_memory * self.DEFAULT_INNODB_BUFFER_FACTOR),
                  self.DEFAULT_INNODB_BUFFER_SIZE_MAX
              )
  
          if innodb_buffer_pool_size > total_memory:
              log("innodb_buffer_pool_size; {} is greater than system available memory:{}".format(
                  innodb_buffer_pool_size,
                  total_memory), level='WARN')
  
          mysql_config['innodb_buffer_pool_size'] = innodb_buffer_pool_size
          return mysql_config